动态场景的快速光线跟踪技术

A fast ray tracing algorithm for dynamic scenes

基于加速结构的光线跟踪包括加速结构的创建和遍历两个过程,kd-tree被认为是静态场景渲染中遍历效率最高的加速结构.但动态场景的光线跟踪,由于场景随时间发生改变,每帧都需要更新相应的加速结构,导致渲染速度变慢.提出了一种新的方法,为场景中的静态物体和动态物体分别创建kd-tree加速结构,每帧更新时只需更新动态部分的kd-tree,从而减少加速结构重建的开销.在CPU+GPU平台上,分辨率为1024×1024,渲染速度达到3～5fps,实现了动态场景的快速光线跟踪渲染.

Ray tracing based on acceleration structure includes two procedures, building and traversal the acceleration structure, kd-trees are considered by many to be the best known method to accelerate ray tracing of static scenes. The acceleration structures are crucial for fast ray tracing and need to be rebuilt or updated as the scene changes. Therefore, the structure rebuilding becomes a bottleneck during ray tracing procedure. A novel algorithm is proposed to build kd-trees for static and moving objects respectively, and it only needs to rebuild or update the dynamic kd-tree while keep the static kd- tree stable. We implement this fast rendering for dynamic scene at 3-5 fps for 1 024× 1 024 images on CPU＋GPU platform.